The operation cable is inserted into the down tube constituting a bicycle frame so as to prevent corrosion of the operation cable and improve the aesthetic appearance of the bicycle.
A conventional cable supporting device is shown in FIG. 6 (refer to Japanese Utility Model Publication No. 61-310). The cable supporting device includes a cable guide 2 disposed in a bottom bracket or hanger lug 1 and small openings 3 and 4 formed in a coupling portion of the bottom bracket 1. The operation cable 5 is guided through the down tube 6 by the cable guide 2 and taken out from the openings 3 or 4 externally.
When the operation cable 5 inserted into the down tube 6 is taken out from the opening 3 or 4, a finger is inserted into the bottom bracket 1 to guide the tip of the operation cable 5 toward the opening 3 or 4 by the finger and at the same time the operation cable 5 is required to be pushed into the down tube 6.
However, since the bottom bracket 1 has not enough space to freely move the finger and the diameters of the openings 3 and 4 are small, it requires much labor and time to take out the operation cable 5 from the openings 3 or 4 externally.